1 files changed, 95 insertions, 0 deletions
diff --git a/plat/juno/mhu.c b/plat/juno/mhu.c
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+/*
+ * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <arch_helpers.h>
+#include <bakery_lock.h>
+#include <mmio.h>
+#include "juno_def.h"
+#include "mhu.h"
+
+/* SCP MHU secure channel registers */
+#define SCP_INTR_S_STAT		0x200
+#define SCP_INTR_S_SET		0x208
+#define SCP_INTR_S_CLEAR	0x210
+
+/* CPU MHU secure channel registers */
+#define CPU_INTR_S_STAT		0x300
+#define CPU_INTR_S_SET		0x308
+#define CPU_INTR_S_CLEAR	0x310
+
+
+static bakery_lock_t mhu_secure_lock __attribute__ ((section("tzfw_coherent_mem")));
+
+
+void mhu_secure_message_start(void)
+{
+	bakery_lock_get(read_mpidr(), &mhu_secure_lock);
+
+	/* Make sure any previous command has finished */
+	while (mmio_read_32(MHU_BASE + CPU_INTR_S_STAT) != 0)
+		;
+}
+
+void mhu_secure_message_send(uint32_t command)
+{
+	/* Send command to SCP and wait for it to pick it up */
+	mmio_write_32(MHU_BASE + CPU_INTR_S_SET, command);
+	while (mmio_read_32(MHU_BASE + CPU_INTR_S_STAT) != 0)
+		;
+}
+
+uint32_t mhu_secure_message_wait(void)
+{
+	/* Wait for response from SCP */
+	uint32_t response;
+	while (!(response = mmio_read_32(MHU_BASE + SCP_INTR_S_STAT)))
+		;
+
+	return response;
+}
+
+void mhu_secure_message_end(void)
+{
+	/* Clear any response we got by writing all ones to the CLEAR register */
+	mmio_write_32(MHU_BASE + SCP_INTR_S_CLEAR, 0xffffffffu);
+
+	bakery_lock_release(read_mpidr(), &mhu_secure_lock);
+}
+
+void mhu_secure_init(void)
+{
+	bakery_lock_init(&mhu_secure_lock);
+
+	/*
+	 * Clear the CPU's INTR register to make sure we don't see a stale
+	 * or garbage value and think it's a message we've already sent.
+	 */
+	mmio_write_32(MHU_BASE + CPU_INTR_S_CLEAR, 0xffffffffu);
+}